Tackling Burkholderia cepacia complex bloodstream infections: Clinical epidemiology, genospecies distribution and novel drug susceptibility in Taiwan

Background: Burkholderia cepacia complex (BCC) showed increasing resistance to recommended therapeutic agents, including levofloxacin, ceftazidime, meropenem and trimethoprim/sulfamethoxazole (TMP/SMX). BCC genospecies have different antibiogram patterns, so genospecies dynamics may affect overall susceptibilities. This study analyzed the clinical epidemiology of BCC bloodstream infections (BSIs), assessed in vitro susceptibilities of novel antibiotics, and explored prognostic factors for outcomes of BCC BSIs. Methods: A total of 122 BCC isolates and 100 episodes of BCC BSIs among adults were enrolled in the present study. We performed molecular identification to genospecies level and antimicrobial susceptibility testing to 12 antibiotics using broth microdilution method by Clinical and Laboratory Standards Institute (CLSI). The all-cause 14-day mortality was used to evaluate the outcomes of BCC BSIs. Multivariate logistic regression was used for outcome analysis. Results: The study identified 97 isolates of B. cenocepacia , 14 of B. contaminans and 11 of non- cenocepacia and non- contaminans Burkholderia . Cefiderocol and ceftazidime/avibactam both showed potent activity against different genospecies. Aztreonam/avibactam and ceftolozane/tazobactam showed similar and even lower activities compared to ceftazidime and meropenem. Source control was associated with better survival (adjust odds ratio, 0.02; 95% CI, 0.003-0.12). Neither combination therapy nor genospecies was associated with 14-day survival. Conclusions: The study highlighted the survival benefit of source control, instead of combination therapy. Further, given the in vitro potency, cefiderocol and ceftazidime/avibactam may play a role to improve outcomes among patients with BCC BSIs.